Electrodeposited nickel nanowires for magnetic-field effect transistor (MagFET)

The growing interest in magnetic nanowires (NWs) is connected to possibility of employing them for advanced applications in wide technological fields, such as data storage and biotechnology. In addition, NWs can be used as sensor devices for several applications, since they present high sensitivity to their environment. One of the major challenges when dealing with transport measurements in NWs is to trap them between electrodes, which allows electrical characterization and therefore fabrication of nanowire-based devices. Electrically neutral NWs can be deposited by dielectrophoresis (DEP) method, which requires the application of an alternating electric field between electrodes. In this work, Ni nanowires (NiNWs) fabricated by electrodeposition technique and properly dispersed in a dimethylformalmide (DMF) solution were deposited on top of Pt electrodes using the DEP method. The deposited NiNWs exhibit initially a Schottky-like current versus voltage behavior due to the high contact resistance between NiNW and electrode. Its reduction down to three orders of magnitude, reaching value less than the NiNW resistance, was achieved by depositing an ion beam-assisted 10 nm-thick Pt layer over the NWs extremities. Therefore, this method presents a suitable process of NWs deposition and electrical characterization. This can be used for investigation of electrical transport properties of individual NWs and fabrication of NWsbased devices, such as sensors and field-effect transistors. Especially for ferromagnetic NWs, one can use the present method for fabrication of magnetic field-effect transistors (MagFET).